You will need:
(1) Your digital camera - I used a Canon Ixus 65
(2) An old or broken SLR zoom lens - I picked up a Sigma 28-200mm from the broken lenses box of a camera shop for 5 quid, I think the autofocus didn't work.
(3) some really tiny screwdrivers, these SLR lenses are held together with tiny screws
(4) Luck - plenty of it
(5) Black electrical tape, various tubes, superglue, elastic bands, anything else you can think of to make a mount for the lens.
Step 1: Take the lens apart
You are after the lens element that sits just behind the front lens element. Keep all the other bits for other projects.