Subsetting contigs from existing .g.vcf's

Hi,

I've used HaplotypeCaller to call variants on whole genome CRAMs without specifying regions. Now, I'd like to subset this data to chromosomes 1-22 + X without redoing the calling. Is there a "proper" way to do this in GATK or I should dive into the structure of the vcf's and truncate the data?

Thanks!