Plusnet mesh advice

[#1]

Afternoon all. I could do with a little advice on upgrading my parents Internet setup now that they have moved to a larger property.
Currently they have FTTC and using the plusnet hub one.
So far I have ordered them an Asus xt9 mesh twin set. Unfortunately I didn't do my homework before ordering the kit. So I have now realised that there is no separate modem and no way of using the hub one in bridge mode.
I've seen brand new hub two's on ebay. Can I simply change their hub one to a hub two, set the hub two in to bridge mode then connect the Asus mesh to the hub two?
I'm definitely not an IT expert though I usually manage to get by with a little YouTube and advice so any tips would be very much appreciated.

[#2]

You should be able to set the Xt9 in 'Access point mode' and use it with the hub1

[#3]

Thank you for the reply. Yes, that seems like an option. Do you see any difficulties using the inheritance method of buying the hub two and changing it to modem mode?
Many thanks, Mark

[#4]

Do you see any difficulties using the inheritance method of buying the hub two and changing it to modem mode?

No, that will work but you will need to configure the Hub 2 for modem mode and if it is ever factory reset it will revert back to router mode.