Its pretty easy to do at home. First thing to do is to get the props/VCU off the car and split the props from the VCU.
This post gives some instruction and has a video for splitting the props away...
https://www.landyzone.co.uk/land-ro...ld-do-on-their-car.312863/page-2#post-4891602
You can then see if the prop splines are OK. If they are not, you should be able to pick up a replacement set easily enough - plenty of Freelanders being scrapped.
If you get replacement props, they will probably come with a VCU - but it will probably be in no condition to use. We have no info on testing a VCU off the car. The only info we have is the 1 wheel up test and that needs to be performed with the props installed.
So you can test with the props as you get them - see if the VCU is OK, and also test it with your VCU.
Obviously, if the props are OK, then the VCU will be knackered - as said its rare, but then so is the splines stripping.
If you need a VCU, the people generally accepted as the best place to go to among Freelander 'enthusiasts' is Bell Engineering...
http://www.bellengineering.co.uk/freelander-1-products/
You'll probably want to get a VCU with support bearings. Its a difficult (I'd say impossible!) job to get ones off a VCU and reuse them unless you have gear to do it.
Before you go spending any money though, I'd check the output from the IRD pinion to make sure it does not turn (just a bit of slack taken up in gear teeth). If that turns freely, then its been converted to 2WD and wont drive the props. It might also be worth changing the oil in the IRD and making sure the old oil does not come out looking 'metallicy' - this would be a very worn IRD that is not in condition to have 4WD reinstated. If they're good, then you should be fine.
ALWAYS loosen the fill bolt on the IRD before draining the oil - and use a good tight fitting 6 sided socket - they are soft as cheese and very prone to rounding.
As I say, these tasks are quite easy, but arduous and take care because the bits are very heavy. The bolts on the ends of the prop are torx - but can usually be removed by 'normal' sockets if you don't have any. It can take a huge amount of whacking with a heavy hammer to separate the props from VCU (see how bent the chisel is in that video) - but it is just a case of hitting it harder
The thing most likely to bring about naughty words is actually loosening the IRD fill bolt.
Good luck. Its actually a really good job to do to get to know your Frelander