Reconfiguring a HG630B as second network device?

Hi. I've been asked to setup network access in a building next door.

BuildingA has fibre and a HG659b providing wifi.

There is an ethernet cable running from BuildingA to BuildingB.

We would like to have BuildingB providing wifi access to BuildingA's fibre connection by re-utilising an HG630b.

I have a fair idea how to go about this, please let me know if I am missing anything or just plain wrong anywhere.

Change DHCP on HG659b(A) to a shorter range, say 10-100.

Change IP address of HG630b(B) to be not the same as HG659b(A).

Set HG630b(B) to bridge/AP mode.

Set up DHCP range with 101-200. (If I turn DHCP off will devices connecting via HG630b(B) get their addresses from HG659b(A)?)

Create new SSID on HG630b(B) that is different to HG659b(A). (The wifi signal from HG659b(A) is detectable in BuildingB but is quite weak.)

Cross fingers.

Will that do?