Am I able to replace my stock HDD in MBP with SSD?

i have an 120 gb ssd [vertex 2]i installed in my 2010 15"core i7 unibody macbook pro,i swapped out the original 500 gig and use this now in usb external for backup,so yes,you most certainly can,and with read/write speeds of 250+ its a good performance boost for certain things,a generally more snappy computer/app launch,startup times etc,and because there is no moving parts in a ssd,less chance of damage due to shock or movement,and less power consumption[apparently]quiter,etc.

it is important to do an erase an install,or do a clone using suitable cloning software,when erasing ,use the minimum option[zero pass erase,]not 7 pass etc!!!!!it has to be formatted[hfs journaled] with disc utility before installing software after restart with osx install dvd,from utilities/disc utility menu in installer window.be very careful,if you open the back cover,to firstly,ground yourself out from static electricity,by placing your finger on a metal surface,[ie dvd drive case]first,before touching anything inside,!!!,hard drives are best handled from the edges,being careful not to touch any circuit boards,or terminals with fingers,you will need to remove the lugs on either side of internal hdrive,and place them onto new ssd,to do this i recommend finding the right tool from here,i think its a small sized hex key ,i used pliars and felt covering,but ive done it many times,and know how to not damage or mark the lugs using this way,

i always clean gently the fan,heatsink area using camera blower whenever i open lid,they accumulate plenty of dust afer a while,so its a good opportunity to give em a bit of a blow out,however dont spin the fans,may damage bearings,its not that hard,you have manuals here,just get the right screwdriver,mini philips head,a good quality one is essential,as weak cheap steel tends to burr screws orslips and damages scratches ,etc,always place scrwes so you use exactly same ones in each hole,and torque up evenly i say,hope this helps,regs ms.ps,i run bcamp/windows on ssd to no woz.

yes,it has to be 2.5 sata 2 form factor.get a more recent one if you can,they have more advanced controller.[indilix or sandforce]