How to get unique somatic mutations for each individual patients
If what you want is to split the main VCF file into 1 file per sample, you could use bcftools query and view commands.

A similar question was asked on biostars, adapting Jorge Amigo's solution to your situation, you might use:

for sample in $(bcftools query -l $combined_vcf)
do
    bcftools view -c1 -Ov -s $sample -o ${$sample.vcf} $file
done