How to corectly tell to a script where the part is?

Hello, in -Workspace- i got 2 Models: -Game- and -Tower- , in -Game- i got a script called -MainGame- , whit that script i want to change a propriety of a model thats in -Tower- called -Long- , soo thats the.. ”link” (i dont know a more apropiate name) that i use,but it doesent work.. soo.. what i should write instead?

L = script.Parent.workspace.Tower.Long (thats the script that i use)

the output says: workspace is not a valid member of Model "Workspace.Game"
Stack Begin - Studio Script 'Workspace.Game.MainGame', Line 128 Stack End

i simply dont completely understand how to explain to the script where is that part called -Long- .