How to mask genotypes in a vcf file

Question

[jmukisa90]

Hi there, I am new to bioinformatics and would like to mask genotypes in a .vcf file before imputation. I would like to mask 5% and 10 % of the genotypes. Any unix code to do this is highly helpful.

Regards

[Pierre Lindenbaum]

please define "mask genotypes"

[jmukisa90]

Thank you @Pierre Lindenbaum for your comment. Masking would mean that you make a genotype missing in a file