Can i down clock a 955 to 95w on a 95w "mobo"?

theoretically, if you lowered the voltage enough then yes.

but im not entirely sure how doable this would actually be (trying to get into the bios when the chip is already installed, and not compatible with the mobo?

also there is the problem that you would lose ALOT of performance. you'd most liekly be better off returning the 955 and get a lower TDP chip.

Wait, I checked the board manufacture's web site and my processor is listed as working with it. I will downclock to be safe though.
The board is a really cheap, spare test board, in case i need a backup board.
I intend to keep it on hand. My CPU is 3.2 GHz, so a downclock is fine with me. I still haven't finished Knights of the old Republic, so i don't really need a blazing fast rig, lol.

ECS MCP61M-M3

It says in its manual that" this board supports CPU up to 95W TDP only".

Yay!