There are 2 steps to this process
1) Remove Trunk Mode
2) Reset to default Access Mode
In the screen shot below the grouping of allowed VLANs is turned off and the Native VLAN is reset to VLAN 1 by preceding the command with “no”
If we look at a show command to see the results of step 1 we should see:
Trunking Native Mode is now VLAN 1