I am brewing a hard apple cider and would like to know how can I increase the ABV % in a cider ? or is it the same process in a beer ?
Alcohol is a byproduct of yeasts metabolism, if you increase the concentration of fermentable material you will (to a certain point) increase the ABV.
The best results are in general achieved by increasing the concentration of natural fermentables, maybe by decreasing the amount of water. If this is hard to do then pouring some extra sugar into the mix will do the trick albeit on the possible expense of flavour.