Putting aside the issues with your current sector...
If you want to do this, the best bet would probably to try and see if you can work with your mate on some of your days off, initially for free, then for whatever he thinks you are worth (hopefully he will be a good chap and not take the pee!) after a while if you are sure it is for you, you can then look at enrolling on 2330 L2 (or whatever the number is these days). After getting L2 and working with your mate for a while you might be in a good position to try and get in with a larger company as an 'improver'
If you want to do this, the best bet would probably to try and see if you can work with your mate on some of your days off, initially for free, then for whatever he thinks you are worth (hopefully he will be a good chap and not take the pee!) after a while if you are sure it is for you, you can then look at enrolling on 2330 L2 (or whatever the number is these days). After getting L2 and working with your mate for a while you might be in a good position to try and get in with a larger company as an 'improver'