Instead of doing multiple conversions, you can use CrossMap to convert VCF (hg19) <-> VCF (hg38). Other than VCF, it can support SAM/BAM, Wiggle/BigWig, BED, GFF/GTF file formats.
Or you can use NCBI remap.
Thank you komal. I have installed CrossMap. I tried to run
It generates following error message
Traceback (most recent call last):
File "CrossMap.py", line 26, in <module>
from cmmodule import ireader
ImportError: No module named cmmodule
Do you think it is not properly installed?