When it comes to fitting, it depends. Both Sensor 2's should be relatively straight forward to get to the connector under the carpet in the footwells. As long as the sensor isn't corroded solid, they should come out easily enough. Bank 1 sensor 1 is not bad, if a bit fiddly to get to the connector. Again, corrosion allowing, it should come out. Bank 2 sensor 1 was a real pain on mine. Connector is back under the under tray, so that needs to come off to get to it. The sensor on mine was corroded up very tight, so to get extra space for leverage, I ended up taking the cross member off that runs under it. I guess it can be made slightly easier if you saw/cut the sensor off so that you can get a standard socket or spanner on it. Unless you have O2 sensor sockets or wrenches, I guess you would have to do that anyway (or cut the lead off at least).
No idea on any paperclip hacks for code reading, I have a cheap code reader which does the job. Some code readers do trigger a vsc/trc error to come up, there is a paperclip hack for clearing that fault code. If you need it, I can grab the piece of paper I have left in my code reader case. Luckily my reader doesn't cause the vsc error, but the one the guy had that I bought my GS430 from put the lights on when I picked the car up. Caused some concern/panic to start with until I found why it had happened.