Halo MCC Legendary achievement

So, i saw this epic armour for Halo 5 which i didnt get to use because i did not have the achievement with all campaigns on legendary done,so i need the help of somebody or more than 1 person for Halo 2 and maybe even Halo 1 which is the one i’m doing solo at the momebt.It would preferably be good if you’re either in the UK or close as I heard the campaign MP is rubbish so it is easier for us to do it faster.I want to get the achievement before H5 comes out so i can have that sweet -Yoink- armour!