Hi Guys,
here's a useful informative video which shows what you'll need to remove the crank pulley successfully and with least difficulty. Clearly these guys know their stuff.

 

Helpful to see an explanation/demonstration of how the OEM silver and black pulleys differ in thickness and why a spacer may be needed with the new pulley.
I had a similar problem with my Eurotoys crank pulley, they sent me the wrong one first (the classic mix-up of OEM silver pulley vs OEM black pulley) and the mechanic who installed it explained that it just didn't fit right and the new belt was also the wrong length. He advised that I might get away with a spacer but even with a spacer the belt would be too tight and would max out the tensioner leaving no adjustment left for the belt stretching over time. He didn't have a suitable spacer available in the workshop so together with the belt problem I decided to scrap the fitting of the new pulley, take it off, refit the OEM pulley, then send the wrong pulley and belt back to Eurotoys to be replaced with the correct pulley and belt, then go back to the shop to fit the new/correct pulley and belt. Eurotoys were very good to deal with and didn't quibble about replacing the pulley and belt for no charge, they were fitted a few weeks later and that was some six years ago now and zero problems since.