The best way is to fix a length of uni-strut just below where you want it to sit. Lift it into position and place the weight on the strut, hold it back to the wall with one had while marking fixing points with the other, lift it back onto the floor. Drill holes and prep your fixings and have them close to hand, lift onto wall and steady in place again and fix with drill driver.
In most settings the strut would be left in position for extra support, just bang a couple of end caps in, but if could be removed if anyone really objected to it (unlikely in in industrial setting!)
