Help with a TEREX TX51-19M forklift on electrical or hydrualic.

So I have a TEREX TX51-19M that is having a Frame wiring harness replaced.. its a lot of freaking work. first we can not get the vehicle to start ( one of our reasons for replacing the harness) and need to lift boom up to a 45 degree angle to put boom lock in. unfortunately this model does not have a manual boom lift method built in... or at least I cannot find one anywhere in the TM. we need to get the boom up ASAP. we cannot get underneath to just disconnect the hydraulic solenoid box to just push the fluid out...

Help with a TEREX TX51-19M forklift on electrical or hydrualic.