extract the positions from genome where reads from all the samples have aligned

[Maulik23]

I have aligned 454 reads from 8 different individuals to the human reference genome using GS reference mapper and converted this alignment into BAMfile now how can I extract the genome positions where the reads from all the 8 individuals have aligned?
I have all ready put marker in read name to identify the individual it belongs to.
Any help will be appreciated

[swbarnes2]

Try BEDTools bamToBed