Go into your lf2 directory, go into the data folder and open data.txt using notepad. It probably looks like this:

id: 0 type: 0 file: datatemplate.dat
id: 52 type: 0 file: datajulian.dat
id: 51 type: 0 file: datafirzen.dat
id: 50 type: 0 file: datalouisEX.dat
id: 38 type: 0 file: databat.dat
id: 39 type: 0 file: datajustin.dat
id: 37 type: 0 file: dataKnight.dat
id: 36 type: 0 file: datajan.dat
id: 35 type: 0 file: datamonk.dat
id: 34 type: 0 file: datasorcerer.dat
id: 33 type: 0 file: datajack.dat
id: 32 type: 0 file: datamark.dat
id: 31 type: 0 file: datahunter.dat
id: 30 type: 0 file: databandit.dat
id: 1 type: 0 file: dataDeep.dat
id: 2 type: 0 file: datajohn.dat
id: 4 type: 0 file: datahenry.dat
id: 5 type: 0 file: datarudolf.dat
id: 6 type: 0 file: datalouis.dat
id: 7 type: 0 file: datafiren.dat
id: 8 type: 0 file: datafreeze.dat
id: 9 type: 0 file: datadennis.dat
id: 10 type: 0 file: datawoody.dat
id: 11 type: 0 file: datadavis.dat

By adding a bit of text to that you'll get just what I did which makes all characters playable. All you have to do is to make a new id. I made a text thing you can add onto it, just put it under the last character on you
list.

id: 12 type: 0 file: datalouisEX.dat
id: 13 type: 0 file: dataknight.dat
id: 14 type: 0 file: databandit.dat
id: 15 type: 0 file: datahunter.dat
id: 16 type: 0 file: datamark.dat
id: 17 type: 0 file: datajack.dat
id: 18 type: 0 file: datasorcerer.dat
id: 19 type: 0 file: datamonk.dat
id: 20 type: 0 file: datajan.dat
id: 21 type: 0 file: datafirzen.dat
id: 22 type: 0 file: datajustin.dat
id: 23 type: 0 file: databat.dat
id: 24 type: 0 file: datajulian.dat