The PCM is normally a small PCB that is linked to the battery, in the case of the link provided you can see some yellow tape on one side of the battery and through the tape you see a PCB. This PCB is the PCM that may need to be removed. Remove the yellow (see through) tape around the PCB and then use some pliers to cut through the PCB just besides the terminals to the battery. You can then use the base of the PCB with the battery terminals to solder the wire onto and then connect the other end of the wire to the Raid card control circuitry. As mentioned before keep track of plus and minus as you do the work, so before you disconnect the old battery and then also where they are on the new one.
Please note that most batteries that you find/buy, will come with a PCM board (which is meant to protect the battery during charging/discharging). If your battery has this module, and you connect it to the RAID card, it will not charge. So either you can ask the supplier for a battery without this module, or will have to remove it before installing on your RAID card. Due to the fact that you will need to solder to the battery terminals, your best option is to snip the PCB just besides the battery contacts and then solder short wires to the PCB/battery contact point, which helps with doing a quick and solid connection without heating up the battery. Ensure you keep track of what is + and -, and that the battery is at least 3.7V (preferably just over, like 3.72V) before you put into your computer.