umps, ramps, wall riding.
accross styled problems, difficulty level is hard and this should be played whot modified handling.
example realistic driving and flying handling line for nrg900 will do the trick.
you need trainer 6.5 to spawn objects
ingame - you should use godmode on bike and save/load menu from teleport after accomplishing difficult part, some of the jumps need previous one succeed to have enough speedfor next jump - in wall riding never cut the throttle or you will fall out too soon.
unrar the file and then place at mainfolder of gta iv where is launch.exe then reload it on trainer ingame.