Quick T-stat replacement question

[nirvana19]

Eh so how much do I want to drain the radiator before? And then just, pull of housing bolts, remove t-stat replace in same position (I guess also drill 1/16th hole above arrow but my replacement doesn't have an arrow.. should be clear though), bolt back up, top off coolant, then bleed system? is that all or am I missing something, need to remove any hoses? Sorry I know this is basic, i've never touched the cooling system except for the fan clutch. M30 engine by the way

[nirvana19]

Thanks! I just began the job and of course, one of the bolts snapped. Wonderful, the other 3 came loose though. Those bolts are only threaded at the end right? Guess I'll be having fun digging that out

[shogun]

No need to drain, that runs out anyway a little bit only. Info on my website under evansweb on the site of Jon Evans how to replace.
No need to drill a hole.
Bleeding: see Gale's website, link also on my site.