How can I safely shrink a size XXL wool sweater to a size XL?

Wash it in HOT water and dry it in the dryer to make it shrink.

I'd be afraid that if you followed luntes advice you might go from XXL
to S. I've inadvertantly dried wool before and it shrank drastically.
It also affected the texture of the wool, making it course. Perhap
others have better advice.

no "safe" way. i dried a 100% wool sweater on regular heat and it went
from about a XL to kids size. I would say if you must shrink it start
on a low dryer setting and see what happens, if it doesnt shrink too
much turn the heat up, trust me it will shrink