How hard would it be to get an engine running outside of the car, as in on an engine. As I want to rebuild my ED engine as a learning experience in case I need to rebuild my EL engine 1 day. So how would I go about running it outside the car?

i guess you would just have to have an adequate fuel system and ecu wiring harness! you would also need smartlock and ignition barrel and all the other crap i guess!

you could obtain an EB series one ecu and engine loom, and run it off some sort of aftermarket high pressure fuel pump etc...

you can do it the easy way ..
you need it to have a flywheel,bellhousing and starter motor .
you can use the ea cfi manifold with the xf carby and slot in a xf distributor and run power to the coil and diszy then just gravity feed the carby..

but be carefull if its just sitting on the ground you might want to strap it down or something because if you rev it it will want to tip over lol