Assuming that it is discs not drum brakes at the rear the best way that I have found (I've had about 15 Peugeots with rear disc brakes) is to take up as much slack in the disc/pad contact area is to jack the car up at the back and manually move the caliper lever - it must be returned to fully back before levering forward again , this ensures that the caliper piston is moving outwards thus pushing the pads closer to the disc once almost there then take the slack out of the cable at the handbrake adjustment end,
You should have 6-7 clicks on the upward travel of the handbrake lever or it will not take up the slack in the future.
It is a little difficult to explain in writing but much easier in practice to do - hope this at least points you in the right direction
If it's got drums then it's another story !