Good excercise regimen for grandpa recovering from brain tumor surgery?

My grandpa (68) has undergone a brain tumor surgery 3 weeks ago (either a grade III anaplastic oligodendroglioma or a grade IV glioblastoma, the histopathology results weren't sure). His tumor was on the right hand side of his brain, in the spot responsible for the left side of the body and vision angles. Thus, I'm looking for some excercises to help grandpa recover for both his left hand and left leg functions and to allow him to start walking more on his own.

Right now, he can walk assisted with little problem (though of course this is more of a shuffle kind of walk than a "proper" walk, as can be imagined but still, he can move all around the house while holding someone's hand no prob) but when not holding to someone's arm, he pretty much can't do it - his left leg just stays behind and he stops, unable to do a step with it. And even though he knows he should pull it up, he knows there's someone right beside ready to catch him, he still can't pull that leg up and put it in front of the other one (which he can do perfectly well if he's so much as holding your hand). As soon as you just give him a hand to hold as a point of reference - he'll put that leg up with no problems at all. Right after being discharged from the hospital, he seemed to have better control of it but since going off steroids according to the doc's recommendation, he can't quite find the way to move on his own (ie. without holding onto another person's hand/arm). Also, while sitting he can operate that leg pretty good - he can rise his knee high up, extend the leg forward, rotate the foot.

What are the post-op physiotherapy regimens you could recommend in such a case that I could try with my grandpa?