Recently I had to tag some Access points to a new Vlan on a Cisco switch , the cisco support website is the worst readability so notes for future reference

Find the Port of the Access point by getting the Mac address then listing all the Macs on the switch via

show mac address-table

Tagging port

Ok next we change the port from an access port on the default Vlan ( 1 ) to a trunk to it can carry multiple Vlans in this case 1,5. Warning this will drop the network device for a few pings

conf t

int gi1/0/21

Switchport mode trunk
Switchport trunk allowed vlan 1,5 

If it doesn’t work you can always wipe the config via

default interface gi1/0/21

To untag a port on vlan 5

 switchport access vlan