A way to copy tracks to a new layer?

Layout
1

Here is my problem. I did a 2 layer board layout and when I did GND polygon pour at the end I noticed that it is highly fragmented and there is not much I can do about it. So, next step is to go with a four layer design. I don’t want to reroute the whole design. Is there a way to transfer existing tracks to the internal layers?

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Edit --> Swap Layers.

This only affects tracks. Copper pour needs to be changed manually.

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Thanks! That did it!