I have the same problem. I just orderd this replacement part:
(and some replacement tools: (www)ebay.com/itm/ws/eBayISAPI.dll?ViewItem&rd=1&item=170522145519&ssPa geName=STRK:MESE:IT
(PS I dont post very often (never) here, so I'm still not allowed to post links... You HAVE to put www in front of the links, otherwise they wont work !!)
In this video someone is disassembling his phone, you can see the speaker when he removes the back of the phone. It doesn't look that hard. You don't have to unplug everything like he does...... It seems like you only have to open the back and then you have acces to remove the speaker.....
I guess it's gonna take a while before my parts arrive. If they do I will post a message wheter the replacements worked or not :P