When I had to replace valves on my bike, I went to my buddy's Harley shop and he uses an attachment on his drill press (turned off). Put the head on the deck and use the wheel or arms to bring it down to compress the springs.
Ok after alittle research I ordered this one (Pit Posse Heavy Duty Valve Spring Compressor part# PP2563) off of ebay and it worked great. E&I motorsports $43 shipped and it got to me in 3 days.
