The alternator itself is fairly easy to replace as there are only two bolts holding it. One is the bolt it pivots on and the other the one that is used to fully tighten it when you have refitted the alternator belt to it's correct tension.
The fusible link is usually located at the battery itself on the positive lead.
To check the alternator you only need to have a volt meter. Place the two leads from the meter on the negative and postive terminals of the battery (red to red, black to black). Check the voltage with the motor stopped. You should have just over 12 volts. Start the motor and check again woith the motor at idle speed. Should still have about the same reading. Rev the engine up to ~ 2000 RPM and check that the voltage rises. Needs to be up around the 13.5 - 14 volts.
If the voltage does not rise, replace the alternator.