--CODED BY V1SIONUSE--
--PUT INSIDE STARTERPLAYERSCRIPTS--
local Players = game:GetService("Players")
local player = Players.LocalPlayer
local mouse = player:GetMouse()
mouse.Icon = "rbxassetid://13335399499"
You can modify the cursors in the %appdata%, local, blah blah blah
I tested it, and it works, but you might have to add it to multiple roblox versions before you find the right version that actually works. It will also probably break every time roblox updates
The path C:\Users[WINDOWS USER]\AppData\Local\Roblox\Versions[ROBLOX VERSION]\content\textures\Cursors\KeyboardMouse
Also, it needs to be 64x64 pixels for it to work properly I think