Just wanted to chime in here because I just dealt with this. I ran my sp2 to about 18k before going to local shop to get quote for service.... they quoted $1200. just for the valves.... meh.
I decided to tear it down this winter to freshen it up, new chain, new sprockets, new radiator fans, new air filters, replace the jenky LED's on the undertail with Custom LED clusters and the valve clearances.
If you have a good metric ratchet set with a drill, some feeler gauges and a few torx bits and hex head bits, you can make pretty quick work of it. Also you'll need a torque wrench... I think the cam journals are tightened to 17 ftlb and the valve covers are something like 7 ftlb.
There is some guy out of europe that has the process on his website, there is a tutorial in motorcyclist garage that gives you the basic idea, and there are downloaded shop manuals for SP1 and SP2 floating around in PDF. Good idea to run your tank down to near empty. Getting gas out/ tank off was biggest hassle for me, but I cannot imagine doing the rear valves without the tank off.
I took pictures, stored bolts and bits from each area in separate little containers. Made sure to check and double check that I had everything top dead center for front and back, measured and remeasured and then when I pulled and replaced shims remeasured to verify I was in spec. .16mm for intake, .31mm for exhaust. I went to the loose side of spec with all my replacement shims because everything had tightened up on me. .13 intake and .25 (average) exhaust so I'm .18 and .33 at all 4 respective valves +.02 which is still in spec.
It took me a minute to build up the courage to do it... But now that it's done and the bike is running like a champ. There is some satisfaction in that.