I have only just started tinkering around with Exbal
First enter all the data fields,no guessing. you will need a Kestral for alt, temp, pressure etc and your bullet info (available on exbal) and bullet speed from your chronograph.
Enter it all in and select zero wind and print off the table it produces.
The next and most important step is to verify the data, I picked a few ranges to do this, I did 330, 600 and 800 for my 7MM SAUM.
Dial in the adjustments for each distance that exbal tells you and do a 3 shot group. If its high or low don't worry just finish the group.
View all 3 groups and work out the average of the three shots and measure if they are high or low and by how much (in whole inches only), don't worry about windage too much.
Then go into Exbal and click the tab "advanced functions" then select 'trajectory validation' and enter the info ie
If your 300 group was 3 inch high type in + 3
If your 600 group was 6 inch low type in - 6
When all entered push calculate and apply.
Exbal alters your muzzle velocity rather than the BC.
Someone else will have far more experience than me with Exbal but this should get you started.
Cheers, Steve