Google it, or ask on BBA Re-man forum.

http://www.bba-reman.com/forums/Default.aspx

Not sure on locations, but there are guys there who can do it. Also check youtube, as plenty of guys who offer the service have ideas advertising on youtube

You can buy various tools, but really it will depend how badly stuck they are. Some are purely mechanical, some hydraulic, and some use black magic.

You could buy a cheaper tool and it might work, it might not. And if the injector breaks, you'll need the professional anyway. So if it is a one off job, just get a pro to do it. If multiple jobs, then it might be worth investing.