It shouldn't be too bad to get it going;
I'm assuming that this is a hydrostatic drive tractor.
I would;
1) pull the glow plugs
2) pour a bit of atf blended with acetone 50/50 into each cylinder, however much fits in
3) start draining all the oils engine and transmission, front axle dif and drop boxes
4) drain the fuel tank and system
5) pull the starter disassemble and clean it maybe even give it new brushes and lube the bearings
6) fill the rear end and transmission 3/4 or more full of diesel fuel, also the front axle drops and diff
7) the engine would be optional but I'd give it a couple of gallons also
8) roll the tractor back and forth several feet several times, vigorously a few times, could even rig a tow bar from the drawbar to a truck;
want that diesel to slosh and splash all around in those cases.
9) if that engine has a bleeder valve on the injection pump open that install a new fuel filter, then try and push fuel into and thru that pump,
if you can get fuel to and thru the injection pump ( or is this an electric common rail system)
10) now I would try and roll the engine over preferably with a wrench on the front balancer bolt
11) if she will turn over your almost ready to go
12) dump the diesel out of everything
13) fill everything with the proper fluids
14) button everything up
15) start it up
16) after she starts and is running move her around get all the fluids circulating and warmed up
17) if she sounds decent and moves
18) drain and replace all the fluids again
19) enjoy
