OK, no arena battle, Goku in his SSJ3 form, gets 3 days prep. GOKU WINS . . . How...you cry? Easy with the black star dragonballs "These special set of Dragon Balls feature black stars (as opposed to dark orange ones) and can call forth a dragon with the ability to cast any wish, with no power restriction" Thus any three wishes right...
01 - Strip LT of his "nigh omnipotence"
02 - Make him have Captain Ginyu's power.
03 - Send him to earth.
Goku then sense's him, and gives him a dragon punch send the Living Tribunal straight to hell Saiyan style.
Oh, in case any of you try get smart those wishes can be changed.