Easy fix.
There is a seal on each end of the camshaft behind the cam gears. If you have no problem replacing your timing belt, you wont have a problem replacing the seals.
Remove the valvecover
Loosen the cam gear bolts
Loosen the timing belt tensioner
Remove the cam cover bolts, remove the cam covers
Slide the timing belt off
Take the cams out
Remove the cam gear bolts, slide off the cam gears.
Pull the seals off, wipe up the area the seal was, and replace them.
Reinstall using the directions in reverse.