To install a soldered connector start by plugging in and warming up your soldering iron.
Caution: Soldering irons are very hot and should never be left unattended. Never use a soldering iron near flammable materials. Follow all the manufacturers instructions.
Strip the wire coating off of the wire to expose about 1/4 inch of wire (if you are using a large connector, more than a 1/4 inch may be needed). If the wire is stranded, twist it to ensure that no stray strands are protruding.
Place the wire and connector on a heat resistant surface. If the connector has a cover, slip it onto the wire first. Next, insert the wire into the opening on the connector. Touch the tip of the soldering iron to the connector where it joins with the wire and hold it there while they heat up. The object is to heat up the connector and wire until they are hot enough to melt the solder. Do not melt the solder by touching it directly to the soldering iron.
Touch the solder to the connector to determine if it is hot enough to melt the solder. When it is hot enough, touch the solder to the opening where the wire enters the connector or to the solder hole on top. Allow the solder to flow into the connector. When no more solder will fill into the connector, remove the iron from the work.
When the connector cools, test the soldered joint by lightly tugging at the wire. It is now ready for use. Slide the plastic cover (if any) into place over the connector.
Caution: Wait until the soldering iron has completely cooled before putting it away.