FX MKII Upgrade to .25

I have an MKII Compact .22 that has the slug power kit installed prior to me purchasing it. I want to upgrade it to a .25 caliber. I'm not familiar with the slug power kit, but I'm wondering if I can just swap out the barrel and pellet probe, or is there more I have to do since it has the slug kit installed?
All you need is a .25 liner the same length as your current barrel, .25 magazine and a .25 pellet probe. Easiest route is a full extra barrel, just remove and imstall the new one.