To override MATLAB's default static javaclasspath, you can follow these steps:

1. Open MATLAB and go to the "Home" tab.

2. Click on "Set Path" under the "Environment" section.

3. In the "Set Path" window, click on "Add Folder" and select the folder where the JAR files you want to add to the classpath are located.

4. Click on "Save" to save the changes to the path.

5. To check if the JAR files have been added to the classpath, run the following command in the Command Window:

javaclasspath('-static')

1. This will display the current static classpath in MATLAB, including any changes you made by adding folders.

Note that the above steps will only add the JAR files to the static classpath for the current session of MATLAB. If you want to make the changes permanent, you will need to update the classpath.txt file located in the MATLAB preferences folder. You can find the location of the preferences folder by running the following command in MATLAB: 

prefdir

Then, open the classpath.txt file in a text editor and add the path to the JAR files, separated by semicolons. Save the file and restart MATLAB for the changes to take effect.