Probably not terribly easy, but the point is this is unlikely to have a concrete result.
If you make the cost of having a factory in the UK greater than cost of moving it, they will move it.
Elbit is absolutely massive, the cost is not going to push it to bankruptcy or to cause it to stop supplying the Israeli government.
Elbit is not likely to be significantly harmed, nor is it going to stop supplying Israel’s military. And they have other options.
I cannot blame Elbit for having loyalty to its home either. It would actually be nice if US corporations had more loyalty to the US TBH.
I have a lot of problems with certain Israeli policies, but I cannot blame Elbit for taking Israel’s side.