Manual mobile mining requires you to be in a TS capable of mounting a Mining gun. Theres only 3 or so that can do this. You also need an Ore Collector fitted.
Find a sector filled with the smaller chunky asteroids, that do not show up on the nav map. Target one. Fire the mining gun at it (at very close range) until it breaks up. Target each piece, and see if it is collectable. If not, fire at it to break it up further. Target the next piece. And so on until all the roids around you are collectable. Then collect them as you would a container or Astronaut by running them down.
Easy in theory. In practice, you end up destroying more than you will collect, and if you hit anything still big enough, it could destroy you.
So, you can use an M5 and small guns to break up the roids, but I recommend using a nice m6 then jump out and give a TS with an Ore Collector, collect orders on the mess left behind. Then get it out of the way, while you jump back in and break more. Dont get a TS to collect dirt while you are IS (In sector), as it will collide with the first uncollectable roid and explode. Murphy’s Law.
Its long hard work for very little, since the act of breaking up the roids inevitably destroys too many of them.
The next option is “Mine Minerals” on the Special Menu, assuming you have special software 1 installed on a ship with a mining gun and ore collector. You tell it a sector to mine, what to mine, and a station to deliver it to.
The best option is using a nice TL or M2 with heavy shielding and the required equipment and then simply running over the asteriods. the shields obliverate the roids and they shink untill they fit into your hold. If your shield go down past 45% Theres nothing that a little SETA won't do.
Warning: The Station sized roids have to be shot with the mobile mining lazer first! Or you will never break it.