Describe update process

README.md

@@ -30,4 +30,15 @@ This software and images are open source and were acquired by Chris Rorden. The
 
 Assuming that the executable dcm2niix is in your path, you should be able to simply run the script `batch.sh` from the terminal.
 
-If you have problems you can edit the first few lines of the `batch.sh` script so that `basedir` reports the explicit location of the `dcm_qa` folder (by default this is assumed to be the folder containing the script) on your computer and `exenam` reports the explicit location of dcm2niix (by default it is assumed to be in your path). Also, make sure the script is executable (`chmod +x batch.sh`). Then run the script.
+If you have problems you can edit the first few lines of the `batch.sh` script so that `basedir` reports the explicit location of the `dcm_qa` folder (by default this is assumed to be the folder containing the script) on your computer and `exenam` reports the explicit location of dcm2niix (by default it is assumed to be in your path). Also, make sure the script is executable (`chmod +x batch.sh`). Then run the script.
+
+## Updating dcm_qa
+
+This software reports when there are any changes in behavior of the software. However, some of these changes might be improvements. For example, software which supports future BIDS tags will report differences relative to the prior solutions reported in dcm_qa. Once the solutions have been verified as correct, one needs to update both dcm_qa and the software that invokes dcm_qa. For example, with dcm2niix we can update it to use the latest version of dcm_qa with this script:
+
+```
+cd dcm2niix
+git submodule update --remote
+git commit -am 'Update dcm_qa submodule.'
+git push
+```