Three ways:
1. Impact
2. Ford shock hex adapter - cost about $9 (fits over shock tit with hex tube for wrench)
3. Good adjustable wrench to grrab shock tit and open end wrench for nut.
If you don't have access to any air tool and the shocks are going to the garbage you can still remove ( cut ) the dust cap and use a pair of Vise Grip on the rod ( chrome part )to hold it still and you will be able to remove the nut.