Before I do something possibly very stupid, can I remove the TDC pointer assembly bolt and lower inner slide rail closing plug without causing something inside the engine to come apart??

I'm working on an oil leak that I believe was caused mostly from a bad gasket on the vacuum pump. While there, I found that the lower inner slide rail closing plug is so loose I can turn it with my fingers. I want to remove it and apply gasket sealer and re-torque to insure I don't have a leak there again.

Thanks
Joe