Alteration illustrator vector file

This design is 150 x 140 cm and will be plotted/cut of this size from a sticker stencil.
At the moment the thin parts of the circles are too thin and need to be minimum of 3 or 4 mm to be able to cut them.

I do like the proportions difference within one circle so they look in perspective but the thicker parts of the circle shouldn't exceed 2 or 2.5 cm.

Let me know what skills you have and if you can alter the circles. It should be fairly easy job.
Thanks