4 to 6 weeks for the glass means that its is a factory sealed double pane.
It gets replaced as a sealed unit.
An acrylic short term replacement can be sealed in using silicone caulking and some mechanical fastening (small brads) so the caulking can cure.
If the sash tilts, generally it is just lifted out of the shoe *small sprung piece on each side of the sash hidden partially in the frame*
https://www.google.com/search?q=how+...g5NoP4cui6AM52
Lift the sash an inch before tilting, then depending on the manufacturer, series, and year... it has different tilt mechanism... tilt the window. Then remove from the shoes like the above video.
If it is not a tilt window then generally the stops will need to be removed. A little more technical, so lets hope it is a tilt sash.