When your offline, removing the web-font import will not prevent the font from displaying if you have the font on your computer. It will only prevent the font from displaying if its viewed by someone who doesn't have the font installed.
If at some point you plan to use the fonts then leave the @import alone and just add an override that you can easily toggle on and off.
body { font-family:arial,sans-serif !important; }
If you only want to affect specific fonts and not the entire document then just search and replace in your editor of choose for the font-family declaration you want to replace.