Cisco ISE - Meraki and WLC wireless

Fellas

I have a customer who has a Cisco ISE 2.4 deployment doing .1x/NAC, RADIUS and TACACS for their Cisco WLC based WLAN environment. Its running stable for past many months. They have recently started to add Meraki into the mix (MXs and APs). Meraki has only been deployed for few remote sites (1-5 person stores/shops). Total 10 sites. But this will eventually expand into the main corporate sites and HQs.

I have been tasked to bring Meraki under the ISE as well. Today the Meraki solution is using a temporary ACS installation for authentication (as part of a proof of concept) but this function now needs to be moved to ISE as the POC has been signed-off as accepted.

I understand that on Meraki portal, for each SSID I'd have to point the authentication to use Cisco ISE. But, what all do I have to do on the ISE side of things? So far I have only added Meraki MX and APs under 'devices'. Not too sure what to do next. Won't the pre-existing auth policies for for this as well? The SSIDs are same on Meraki and WLC-based.

I am operations guy and haven't stood up ISE from scratch, but, this seems not too complex since everything is already setup and functioning on ISE for the WLC based WLAN. I need to do the same for Meraki WLAN. Please guide me!