Replace gta3.img files in the archive:
GUN_BOXWEE.dff
GUN_BOXWEE.txd

Skate is ryados the house of Charles.
Raise Skate - click on "TAB"
Put Skate - click "Exit MACHINE"
Hang on his back - click on "Next weapons"
Weed in the car - then "take the car"
To go to skeyte - click on "TAB"

press "accelerate"+A or D - move up.
press "accelerate"+A or D+specUP - Jump bonus.
understand?