The surya namaskar is the first thing most people lose and the first thing they try to get back. It is a good choice — it warms the whole body and asks little in the way of equipment or thought. But the version in your memory is not the version your body will give you in the first week. Expect that gap, and do not let it stop you.
The first ten rounds.
In the first few rounds the breath will run ahead of the movement. This is normal. Slow the rounds down until one breath carries one movement — inhale to reach, exhale to fold. If you arrive at the bottom of an exhale with movement left over, you are going too fast.
The shoulders and wrists will speak up before the legs do. Lower the knees in the plank and the lower-down for the first week; there is no prize for holding a full chaturanga on a body that has been away. Build the load back slowly. Ten honest rounds with knees down will serve you better than three with perfect form and a sore wrist tomorrow.
By the second week the sequence stops being a series of poses and becomes one continuous shape again. That is the sign to add a round or two — not before.