I have posted some blogs on Sandya Vandana dealing with the importance, Rationale ,the procedure and posture to be followed.
This Audio post contains the First part,Poorvanga of The Sandya Vandana.
This is to enable the user to play the Audio to perform Sandya Vandana and contains only the mantras.
To be conversant with the details please read the other posts.
One important point.
There is a misconception that only the Brahmins are permitted to perform the Sandya Vandana.
This is wrong.