The DH parameters will be wildly different from your new model.

Starting from the first joint, locate the DHParameter node.

Adjust the d, theta, r, alpha values to match your new robot arm. You will see the blue and red lines change.

The sequence of moves is always translate along z (d), rotate around z (theta), translate along x (r), and rotate around x (alpha). See this video for more information. The DH point of rotation might be somewhere unexpected, even outside the model. It is very possible to design robots that cannot fit in DH parameters, but that's a subject for another day.

If you now attempt to move the arm, mesh files will still move incorrectly. With the arm at the default position, Press To Pose to fix them.

Only use To Pose in the starting position. The explanation is too long to fit here.

Make sure the End Effector at the last link has the blue line (Z) pointing out of the hand. This way tools will attach correctly.

When you are done it should look like this. Colors should be correct and moving should work correctly. Your joint limits will be fixed in the next step.