Accept a text file of Hex values and convert to decimal

Question

Example:

 

Here is the hex value 00037FFED3837801.Want to change it to decimal value --985157377161217

which I usually do using the below link. http://www.binaryhexconverter.com/hex-to-decimal-converter  .Need help in this context as they are almost 2k values to be converted.So trying for a program which can accept that file of 2k values ,convert them to decimal values and display.Could you please help me in this?

 

Thanks in advance!!