Expanding a PtP subnet remotely?

I am in the process of expanding our network and need to adjust the IP and the subnet of a remote switch. Currently there is a /30 point to point going between two of our offices. I am now adding in a pair of Dell S4048-ON switches running VLT and peer routing as the core in place of a single core switch. Looking to expand that point to point subnet to a /29. Would I be correct in my thinking that to do this correctly I should first login to the remote switch and update the IP and subnet on the VLAN. Once I then lose the connectivity across the network then go ahead and adjust the IP address on the other switch to be in the same subnet. Is there anything else I should look out for?