This diagram shows the configuration of the pas, alternator and a/c V-belts on several engine types including the 2C/2CT for Townaces, for which there was a small change around August 1990 - when the the alternator drive was increased from one to two identical belts side-by-side.

The order of doing things is:

Taking drivers seat/floor out is described elsewhere. If you are only doing the V-belts you can remove the four bolts holding the gear shift instead of disconnecting, but still have to release the hand brake cable. Remove the fan shroud - 1 bolt each corner. If you have a plastic cowl covering the bottom of the engine in way of the bottom pulleys take it off for easier access.

Remove the four 10mm AF nuts that hold the fan pulley, and viscous coupling on to the engine. You can then take the fan out of the way and the pulley will come off, slackening the alternator belts. It is just possible, with care, to put this all back later without swinging the alternator in.
Power steering pump belt. (3 ribs. Toyota p/no 90916-02122) Try to slacken the hinge bolt - difficult to get at. Slacken the retaining bolt on the semi-circular guide and pull into tension before re-tightening as normal.
Alternator belt(s) (also drive(s) fan and the vacuum pump built in to the alternator). (Toyota p/no 90916-02169 or 2x 90916-02315 or 02381) Slacken the mounting bolts and the 12mm (?) bolt you can see down the side of the alternator that tensions the belt(s) - best accessed with a universal socket extension piece.
Aircon compressor belt. (Toyota p/no 99332-60835, Gates equivalent 6463MC £6) Loosen the centre 14mm AF bolt in the tensioner/idler pulley then slacken the 14mm AF tensioner bolt underneath at the front of the sump - once you've seen/felt where this is you can turn it easily from under the driver's side of the car with a long (40cm) extension. It unwinds a long way - until the idler pulley touches the compressor pulley.

Finally getting to the Timing/cam-belt (or cambelt, drives camshaft/valves, fuel injector pump, oil pump and water pump, see RM025E manual). (QTB139, Toyota p/no 13568-64011; 3CT:13568-64012=power grip 177r25) Replacing crankshaft pulley/timing belt (1992 2.0TD lite Ace). The biggest probs are getting the timing pulleys off without breaking them - and believe me they are brittle!
It seemed a horrendous task but actually it’s not that bad. Never having done this before the disassembley took about 2 to 2 1/2 hours and the re-assembly about 1 1/2 hours. Remove the bolts surrounding the timing cover. This will allow you to better remove the Crankshaft pulley.
Take care removing the crankshaft pulley (it'll fall off if it was loose!)If it feels partially seized you need to lock the Crankshaft pulley to prevent the crankshaft turning. OK if its a manual - put it in gear, that will help but not guarantee it. You may have to resort to putting a spanner/short screwdriver/bar between the spokes of the pulley and the sump/block to prevent the crankshaft turning, or even made up a piece of flat bar to lock up the pulley. Then loosen the crankshaft nut 19mm I think. Obviously you should not use EXCESSIVE force. Careful removing the Crankshaft pulley with the keyway at the top so the key doesn't fall inside the timing cover (the clearance actually allows this to happen?). Here is how I get my crankshaft pulley off with two of the pas pulley bolts lightly sandwiched between two steel strips 74x14mm, held in place by two other small nuts+bolts. I (a) oiled the two pulley bolts and screwed the big bolt right in (b) tightened the two pulley bolts so my puller was hard against the pulley, then backed them off 1.5 turns. (c) unscrewed the big bolt hard against the puller, checked the plates were held securely in position by the tiny bolts, finger tight (d) tightened the two pulley bolts 0.5 turn at a time until the puller was hard against the pulley again (e) repeated (b) to (d) until the pulley was loose.

Check the machined groove in the pulley to ensure it's not damaged or that the key has not turned in it. If it is damaged, replace the pulley! (Circa 200 quid) If it's not damaged get a new bolt- about 2 pounds 50 pence. Get a new key at about 70p.
Timing marks are one at 3 o’clock on the cam shaft pulley, one on the pump, and one as a "v" indicator on the crankshaft timing belt pulley.
Be careful replacing the crankshaft pulley to ensure your key locates well into the slot in the crankshaft - lots of light and peeking behind the timing belt cover! When replacing the nut use a good quality threadlock compound (Loctite).
Rebuild in reverse order. If I recall spanner / socket sizes required are 10,12,14.17,and 19.

The following is of uncertain origin but probably refers to Spacecruisers...
QBB850 : Belt 1 (Alternator) 1986-June 1989, 12mm x 850mm OD £6.23 (The prices shown for the belts include vat and postage)
QBB925 : Belt 1 (Alternator) July 1989-1991, 12mm x 925mm OD £6.79
QBR51205 : Belt 2 (Power Steering with Air Conditioning) Ribbed £9.02 (Ribbed part numbers tells you the amount of ribs, in this case 5, and the remaining digits being the outside diameter)
QBR51113 : Belt 2 (Power Steering without Air Conditioning) 1986-May 1989, Ribbed £9.89
QBR51110 : Belt 2 (Power Steering without Air Conditioning) June 1989-????, Ribbed
QTB139 : Belt 3 (Timing Belt) 177 teeth x 24mm width, £16.34 Editor - Feb 2004