There are some trainers to do it but they probably haven't been updated to work with v11.3.
You can change remap by changing the mis files with GTA2 mispad or scriptpad. Level 3 is the only level that has the .mis files available, so if you did it on other levels, you'd lose all missions.
Using GTA2 SCR Tool
is easiest and it should work on any SCR file without the mis files but I think it might make some scripts unstable. This post has been edited by Sektor on Sunday, Mar 10 2013, 21:04