That's as far as I went - the zoom was no longer jammed, and reassembly was the best option here! Reassembly is the reverse of disassembly
The aperture unit/rear element is slightly tricky to put back. Make sure you align it correctly (lens nearly at 35 mm, so that the screw holes are high up).
Remember to blow dust out of the lens if you see any as you are reassembling it. Do not use anything liquid to clean the inside of the lens unless you know what you are doing.