Machewski's guide is great.
However, if you're like me and had already done all of the easy ones, there's an even easier (and more fun) way to do it.
Hit
, go to Peggle 2 and press
, go to "Manage game & and-ons", down to "Saved data", "Delete all", "From everywhere".
This causes you to completely restart the game, BUT, you can now play through again, and all the objectives you do WILL count.
This is probably faster in the long run, as you won't get dragged down by the grind.