The list of things to do says:
FOCUS ASS'Y, USM
LENS ASS'Y, 3&4 GUIDE BARREL
COLLAR DECENTERIG REPLACE
And the written description was "need to replace an expensive part and takes a lot of time".
Taking a lens apart is doable, but keeping it dust-free when putting it back together (if you don't need replacement parts) is not so easy at home. So the options would be to have a lens for 600 euro, or have a toy/paperweight and a new lens with guarantee for 1000 euro...