So since GW hates us and likes to make us jump through hoops of all sorts... I am now looking at the task of upgrading my 200ish+ Chaos Space Marines from 25mm bases to 32mm.
Luckily a company called Eccentric Miniatures sells these sweet ass Base extensions. Just glue them on the existing Base, and BOOM, 32mm. I started on my Plague Marines first and they work great.
Had to experiment with glue, and found my old stand by, hot glue, works the best. Just got to be careful and not use too much ha, which is tough for me since I fucking love hot glue!