This is the procedure to follow:
1. Navigate to 192.168.0.1
2. Log in to the Hub
3. Go to 'Modem mode' (on the left) and put the hub into modem mode
4. Wait until the bottom light on the Hub turns magenta / red (HUB 3) (can take about 5 minutes)
5. Turn off the Hub
6. Power on and set up your new router as per the manufacturers instructions - Set the same SSIDs as the hub if you want - then your devices should just reconnect!
7. Plug an ethernet cable (usually supplied with the new router) from port 1 on the Hub into the WAN (usually blue) socket on the new Router
8. Power on the Hub and wait about 5-10 minutes until it stabilises - You should have internet!
------------------------------------------------------------------
Hub 3 - Modem Mode - TP-Link Archer C7