Volvo Penta Outdrive SX-A - Stripped threads on oil fill/overflow hole - proper way to repair?

[vetting]

Trying to help a buddy who has a stripped oil fill/overflow hole on his Volvo Penta outdrive.  With the high cost of a Volvo Penta outdrive failure, we would prefer to do this the most proper way possible.  Is the correct way to remove the housing and take it in to get a proper helicoil or time-sert?  Drill and tap and find a larger plug?  If removing that housing, what does it all entail and is there any realignment procedures?  
Thank you in advance for your help.  

[HB2]

Hellicoil? 

[Lucky D]

if your going to retap threads coat tap in bearing grease the grease will catch all your aluminum chips and a shop vac wont hurt to help catch small chips