Moving four year old apple tree

One of my plot neighbours is moving sites to a new site that has opened beside him but the plot he will have is less than half the size of his current one (he has injured his back so this suits him better).  He has a lovely four year old apple tree that he can't take with him so he has offered it to me.  Would it be possible to move it.  He is paid up on his plot until next April so no urgency on moving it.

RHS advice here:
https://www.rhs.org.uk/advice/profile?PID=293

I was given a well established apple tree by a neighbour - its been fine and is now in its second year on my plot and looks like I'll get a decent crop this year.

As NorfolkGrey said - move when dormant and with a big root ball... fingers crossed!

Pip pip,
Balders