✓ Accepted answer
Don't
If the FilteringEnabled property of Workspace is not enabled, you should already be able to do this. If it is enabled, you will not be able to access the members of the PlayerGui (Assuming they came from StarterGui or were cloned by a LocalScript)
For security's sake you should not put Value objects in GUIs unless they don't mean anything as you should assume the player can change it. Remember: never trust the client.
Anyways, here's how you could do it with a RemoteFunction:
- Create a RemoteFunction and put it in ReplicatedStorage
- Have a local script set up the
OnClientInvoke callback
- And then return the value, so then in the server you can call
InvokeClient with the player you want.