The current problem i have now is that i don't have any idea how to attach the IAC motor to VEMS.

Here is a picture of the IAC, the left one


And the pinout is the bottom one in this picture


There are 2 possibilities for direction (good or reverse). It can be tested with mdi.. command (mdi01 .. mdiff for min to max forced iac position. mdi00 is automatic PID control). if it's reverse, it can be corrected with a wiring change or in config: iac_step_sequence ( See MembersPage/MarcellGal/EngineSwap/AirFeed for old but likely appropriate notes)