Take the capacitor off. Make use of solder flux at both sides of the new capacitor.
The following step is to take off the coatings and insulations on the leads by using sandpaper or an emery cloth. The capacitor will most likely contain a polarity plus terminal and one terminal with minus. Clean any remaining solder by using a knife or file prior to reinstalling the capacitor in its original location.
Reattach any wire connectors after installing solder on both terminals of the old capacitor which you have removed. Take off any insulation on both ends of the wire connector. Then, connect the wire connectors securely to both ends of the leads after applying solder to one of the ends. You must ensure that the wire connectors are set so that they don’t reduce the length of the lead.
If you are soldering a capacitor you should follow the proper voltage rating in volts typical for all capacitors. A capacitor that is 500 volts which has a voltage of greater than 250 volts. A capacitor with the rating 500 volts would be considered a 1,000-volt capacitor. Place the capacitor in its correct place on its mounting strip with the terminals facing the other.