I had this same question last year. I couldn't find an answer so I can't answer your question directly but I can tell you how I did mine.
I rotated the hub so the bolt holes were located so that any lube seeping out would not get into the bolt hole. I then used brake parts cleaner to thoroughly clean all lubricant in the bolt holes and on the bolts. I applied LocTite Blue liberally to the bolts, positioned the bearing cover, installed the bolts and tightened them tight but not too tight.
For the record a standard 8mm bolt torque is nominally 20 ft/lbs. My thought was 20 ft/lbs might be too much and cause the plastic bearing cover to warp.
If I remember correctly the bearing cover has metal sleeves in the bolt holes that would tend to reduce any warpage...maybe 20 ft/lbs is the right answer. Keep in mind that there is no mechanical stress on this part. It is just needed to hold the cover on. The LocTite helps insure that it does't loosen. Specific torque to guarantee that mechanical strength is maintained is different than if you were bolting an engine together.
I've run about 5K miles since installing the bearing covers...no leaks!
I hope my ramblings have been helpful.
2003 34' Georgetown on W20 Workhorse Chassis. UltraRV power mods. Front Sumo Springs, Rear P32 Sumo Springs, UltraRV Track Bar.
1998 Jeep Toad.