There are two ways to get ACID:
1. To download the current version as a ZIP file click on Download button (see nagivation bar, left-bottom). Unzip the file, rename the file to ACID, and put it into the toolbox folder in your spm directory
2. To never miss an update set a GIT bookmark. Place your working copy into the toolbox folder in your ACID directory
Then start SPM as usual, for instance by typing
>> spm fmri
Generally, the toolbox will work now.
C-files might need recompiling
In circumstances, where the toolbox does not work immediately, recompiled the c-files. In order to do this, launch Matlab in the directory SPM/toolbox/ACID/cfiles. Start the compilation by the file:
Furthermore, launch Matlab in the directory SPM/toolbox/ACID/Preprocessing/HySCO. Start the compilation by the file:
The SPM GUI
In the SPM GUI, please click on 'Batch' to open the Batch editor.
In the top menu under tools, there should now be an item 'Artefact Correction in DTI' from which the ACID tools can be accessed.