The tensioners have a crush ring on them (you can see it near the hand in the small pic.) that is replaceable. An oil leak at the tensioner seal is not a sign of impending doom; it is just an oil leak. Now comes the fun part; you cannot replace the crush ring without removing the tensioner; and you cannot remove the tensioner without first locking the engine at TDC:
And then securing the cams so that they do not move (jump time) when the tensioner is released:
After which you can unscrew the tensioner, put on new crush ring and a new o-ring on the shaft, and re-torque it. Simple, isn't it? Before going through all this, I'd suggest making sure it is torqued to begin with.