Dividing Zygopetalum

[PragmaticOrchidGrower]

Hi

I have several Zygopetalum types that is growing out of their pots and finally I have a green house that I can leave them out in and give them appropriate temperatures (and maybe even better humidity as it gets below 40% indoors during winter!!). So I'd quite like to divide them and thus get more plants out of it..... and I think the plants prefer the same (one of them actually broke the pot with its roots!!)

I have never really done this before and was hoping for a few good tips and hints.

They all have new growth going at the moment. I'm using plastic pots and bark, mainly because that's what I can get my hands on in normal plant shops around here.

Thanks!