There is only one way to unite the party...and that is a Trump-Cruz ticket. Unfortunately, both men seemed to be burning those bridges on a daily basis so its going to be very difficult to bring things together. That said, political necessity can be a powerful force that sometimes overrides personal disdain and even hatred. A nice start would be for both men to change their tone towards one another...and as a Trump guy,I will acknowledge that it is his burden to start that process of dialing it down. Once you secure a Trump-Cruz ticket, you will have to give some nods to the establishment types with some promises of filling key positions...not a big price to pay considering what is at stake. I believe Trump has the skills to mend these fences and bring the party together, but it will require a sustained effort at civility and a lot of back channel negotiation.
If these two men cannot get together, I fear we are doomed whoever wins the nomination...because, as many have said, if either walks away feeling cheated they will take a substantial chunk of the party with them. If that happens, we all lose and Hillary gets to pick the next 3-4 SCJ's.
IMHO, the NeverTrumps and NeverCruz's need to shut their pieholes, and both candidates need to start accepting that they ultimately need each other.