If is only dripping its fine, now if you have residue all over the chassis around the clutch and front of the engine there's a problem.
The trx engines are made to have a small bit of oil leak out of the front bearing, theres actually an oil port for the front bearing drilled through the case near the carb.
Any way to replace it you have to completely dissemble the engine and heat crankcase up to 250-300* from there you should be able to push the bearing out with a chock of wood and a hammer repeat the process to get it back in.