First remove the battery and antenna. Separate the case by removing the four black phillips screws and two bottom silver phillips screws (leave the two top silver phillips screws alone).
On the half that has the PTT switch and 'front' of the radio, locate a bank of diodes just to the right and below the printing 'UHF'' on the circuit board down near the lower right side of the board.
There are four of them, three black with 'AY' printed on them and having three leads on them, one silver having the number '18' on it and only two leads.
If you are holding the radio parts vertically, (the printing 'UHF' is right side up), then the block of four will be:
Using a micro solder iron with a pointed tip - be careful to apply just enough heat to loosen the top '18' and 'AY' diodes and lift all but one of the leads off of each with a jeweler's screwdriver or the tip of an x-acto knife. By leaving one of the leads attached you have the option of reattaching them if you choose to. These diodes are so small you would otherwise lose them and if you ever need to send the radio back to Icom for repair the warranty would be voided. I also use a loupe to better see what I'm doing.
Because there's not much clearance (these things are about the size of a pinhead) you have to be VERY careful with the soldering iron.