why does it end with .rar?
As for tutorials:
- Correct steps to form an interferogram: http://step.esa.int/docs/tutorials/S1TBX%20TOPSAR%20Interferometry%20with%20Sentinel-1%20Tutorial.pdf
For Differential Interferometry, make sure you include the topographic phase removal in the inteferogram generation step. - Unwrap the interferogram: https://media.asf.alaska.edu/uploads/pdf/current_data_recipe_pdfs/insar_phase_unwrapping_v5.pdf
- Convert to Displacement as described here: Subsidence map in 3d view