Stripped screws oil access cover

[Apexpat]

Trying to change the oil on my 13 Apex this morning. Put the 4mm hex socket on the screws for the oil access cover and both stripped out. Once I get them out I want to replace with a hex head bolt. Anybody change these out and know the correct size?

 

[Snorunner]

Trying to change the oil on my 13 Apex this morning. Put the 4mm hex socket on the screws for the oil access cover and both stripped out. Once I get them out I want to replace with a hex head bolt. Anybody change these out and know the correct size?

My guess would be 6mm diameter