Not sure I'm creating a new subnet at a remote site properly. Would you mind looking over my plan?

Hey everyone, I was hoping to get some guidance on creating a new subnet at one of my remote sites. I'm still a bit of a novice when it comes to networking, so I'm not 100% confident in what I need to do. Part of the reason I'm cautious is that I do not have physical access to the site (4 states away), and no one onsite has a lick of technical competence. Also, I don't have much of an opportunity for a maintenance window or planned downtime.

At our largest manufacturing plant, we have 6 Cisco S2960 workgroup switches, a Cisco 5508 WLC and about 40 Access Points scattered throughout the plant. Whichever predecessor implemented this, they did it the easy way.

The network there is 172.16.1.0/24. There are only 100 available addresses for DHCP. Naturally DHCP was set up on the Windows server with all defaults, so the lease time is 8 days. With the growth of devices at the plant the DHCP scope is frequently exhausted. Here's a simplified diagram:

https://i.imgur.com/B2LasDU.png

So I want to create a new subnet out there just for the wireless infrastructure and clients. Static addresses for the APs and 4 hour leases for any DHCP clients.

1) Create a new VLAN on the workgroup switches interface Vlan5 description WiFi VLAN ip address 172.16.101.1 255.255.255.0 ip helper-address 172.16.1.10

2) Create the new DHCP Scope on the server with 172.16.101.1 configured as the router in the scope options

3) Set an unused port on the MDF in the server room on the new VLAN to test interface GigabitEthernet1/0/2 description WiFiVLANTestPort switchport mode access switchport access Vlan5

4) Have someone at the site plug in a laptop to the new test port and ensure they grab an IP from the new scope and they're able to access all network resources.

5) (Here's where I'm really unsure) Identify the ports that the access points are plugged into and set them into switchport mode trunk and allow both VLANS?

6) Log into the Wireless controller and change the IP addresses of the Access Points to the new subnet

7) Reclaim the old AP ip addresses and add them back into the original DHCP Pool.

8) COPY RUNNING CONFIG TO STARTUP CONFIG

Is there anything that I would missing or doing wrong? Do I need to modify the port that the Wireless Controller and/or Server is on in any way? I shouldn't need to do anything on the Powerconnect switch right?

Thanks in advance!