There are no special ways to pray it, really, that I know of. Just say it as it is normally said, but between mysteries or at the end I would suggest saying aloud intentions for grandpa as a special way to sort of include him or make the prayers more meaningful. Again, as far as I know, there is no different way of saying it...
Just pray it as you would normally pray it.The Lord will always listen.You could also do a special Novena.A Novena is when you pray a special prayer every day for 9 days,for a special intention.So if you pray the Rosary every day for 9 days,and think of your grandpa while your doing it,and pray specially for him,then that will be a really good Rosary Novena.You could ask his favourite saints to pray it with you and they will intercede and help you to pray.If you don't have time for a decade a day Novena,then you could just do a half-decade one.The second day of November is all souls day,so you could start it then if you wanted it to be extra powerful.I will also say a prayer for you.God bless.
