Enter your Dojo
Go to the Tenno Lab or any room with a Warframe Arsenal access point
Interact with the Arsenal
Select your Warframe
Choose the frame you want to equip
Confirm the selection
Leave the Arsenal
If you mean changing the room’s decorative frame or display, use Decoration Mode instead
Open the Dojo decoration interface
Select the frame or display item
Replace it with the desired one
Confirm the placement