Expand the court to more justices (the law currently sets it at 9 although there is no constitutional upper limit) and simply appoint them and have the Senate confirm them. But the more I think about it, with consideration of the comments above, this might not be a good idea for Trump because it would be seen as a blatant attempt at a power grab.
I had no idea they could expand the court.
I agree though, either party that does that in order to gain the majority is going to be met with a lot of criticism. We can get a majority by Trump appointing someone now.