How much room have you got behind the pulley for the puller?
Are there any threaded holes in the face of the pulley?
You'd need a fast acting puller because you need to move the pulley a long ways and you've only got a few seconds of heat differential to get it moving. A common mistake of amateurs is to use too small of a torch, and heat around the center of the pulley. That won't work at all. You need a 1" rosebud, oxyacetylene is hottest but Flamex will do. Heat round and round at the rim of the pulley. You must get the rim hot to make it pull the hub outwards so it will relax its grip on the shaft.
A heavy 3 jaw puller will be most stable, and you'd need it done up tight to start. Avoid pausing the torch directly over the puller tips because you don't want to wreck the puller jaws. Have a man ready with an impact socket to spin the screw quickly as soon as you hear it crack loose.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)