Firstly, be assured this is not rocket science! Others have posted on this forum, as have I in the past, so you could just search for it.
For LRT - 51-008, you can use something like a piece of pipe or as I have done an old box spanner of the correct size so it leaves clearance for the spigot to rise inside it but will rest on the pinion flange. Then you assemble a bunch of washers, thick as you can get which will sit on top of your pipe/box spanner. Through the central hole pass a piece of threaded bar, with a couple of nuts locked together on it, of the correct diameter and thread to go into the threaded hole, M8 if memory serves, but I did it on a D1 and it may be different on a D2. Tighten the bar down into the hole. Then, ensuring the hole in the centre of your washers, if too big, is reduced by using penny washers of narrower internal diameter, thread down a nut and start tightening it. This should pull the spigot upwards inside the pipe/box spanner. It WILL be tight, others have used heat, and as you are replacing the seal then a heat gun will not do uncontrolled or unwanted damage. I personally used a slide hammer and all sorts before realising that the use of what is in essence a puller is really the only way to go. You should also soak it in Plusgas, WD40 or a mix of ATF and acetone to reduce the grip of the flange on the spigot which is donw to a form of Locktite or something.
Once it is out, LRT -51-003 really isn't necessary. If you are doing this on the car, all you have to do is lower it to the ground, chock the rear wheels, handbrake on then undo the pinion nut as normal although it is done up to a heck of a torque. If you have taken the diff out, then just jam the pinion teeth against the crown wheel teeth with a big screwdriver or something similar to stop it turning.
If you really want to replicate the proper tool, you do not need a bit of bent flat bar, a longer piece of flat bar will do. Off to B&Q, get some bar, cut a bit off, drill some holes use a bolt and nut to secure one end of the short bit of bar to the long bit, then use the existing nuts and bolts off the flange to secure the holes at the end of your bits of flat bar to the flange, hold the long end of the bar while loosening the pinion nut.
Then pry the old seal out carefully to ensure you do not mark its seat etc.
Best of luck and let us know how you get on!
