Ruben, The axle support bearings have two holes in them so you can screw them in place against the hull,
Make sure the holes in the hull are placed so you can get access to the screws so you can fit the nuts, because the gearboxes do get in the way!!!
If your Hull is fitted with axle covers, they will need taking off before the support bearings are fitted, a liberal application of debonder will do the job and after you have cleaned everything just refit.

shaun