The only risk with replacing the cam is pulling the threads on the cam bearing mounting bolts. These bolts go through the head, into the engine block. If you remove the threads with the mounting bolts, the only way to fix it is to remove the head and heli coil the block. Turns a relatively easy job into tearing the whole top end of the engine.
1989 560SEL (172k)
1989 325IC (122K)
2004 Suzuki Volusia LE (3500 miles)
2005 Yamaha Road Star (20 K miles)