Changing land register from deceased person

Is it easy to change the land register from a deceased person to two beneficiaries who will be tennants in common. And is it possible to put on restrictions so that one can't sell without the other thank you 

Hi Mary - see our online assisted guidance for how to update the register following the death of an owner - HMLR Guide: Start - External  · HM Land Registry
Such applications can be 'easy' to make but please do seek legal advice as appropriate to consider what's best especially re your Q re selling without the other's permission. If two people are registered as the legal owners then any sale would have to be by both of them.