Frequency is of course the same in and out.
Pick some sensible R1, like 1k. The current through C1 is C1·dV/dt, where dV/dt is the output rise/fall rate in V/s, and it is essentially equal to the current through R1, which you calculate easily. Pick C1 such that you get the dV/dt it takes to reach the desired amplitude in each half of the signal period.
Pick R2 such that R2·C1 is greater than 10x the period in seconds, i.e. 10·0.001 for 1kHz. Increase for less distortion, reduce for better output centering around zero. If unpractically large, try again with lower R1.