Using the Bondtech SLS X - Carriage kit for Prusa i3 MK3S is straightforward. First, make sure your Prusa i3 MK3S is turned off. Then, install the SLS X - Carriage Front and Rear parts as per the instructions that come with the Bondtech Upgrade Kit. Use the included 5x M3x10 Screws, 5x M3 square nuts, and 1x M3 nut to secure the parts properly. When it comes to working temperatures, remember that if you're using this kit inside a closed chamber with a Bondtech Upgrade Kit, the sensor plastic parts can handle up to 60°C (it can go up to 90 - 100°C if the parts are annealed), and the stepper motor can tolerate up to 80°C. Don't exceed these limits to avoid any damage. For maintenance, keep the parts clean. You can use a soft brush to remove any dust or debris. If you notice any signs of wear and tear, it might be time to replace the relevant parts. And always store the kit in a dry and cool place when not in use.