Well, first thing first, William. Let's take this matter apart bit by bit and find what we can do about it. Jason pulled himself from the seat and walked over to the bar. Meanwhile the other two were left to their own to think of this soon-to-be-problem. Hea reached the bar maid and asked for a Rheinbier. Leaned against the counter as the girl was fetching his drink. Picked it up, payed the few credits for it and walked at the table, taking his seat back. So, here are the few distinct problems I see here:
Getting a survey of the area, a rough count, to see what we are facing here. The difference in the actual density compared to it's intended one should give us a rough estimate of how many mines we would need to replace. We should ask the latter from the Overwatch.
Acquiring these mines, in some way. Maybe producing them?!? Again, Overwatch should have data concerning this.
Hauling them to the job site. Mind those are nasty devices, so I do not think the regular transport ship would do.
Replacing the missing mines and packing closer together the ones already existing. This is what I see as the most difficult in this whole job. Again, we will be needing a special vessel to withstand a few accidental blasts and still be able to move around all that mass accurately.