To perform a local update, it is necessary to download the required version, in this case, v1.86.1827. To download it, you can visit the website https://www.epcom.net and search for the model you have, in this case, the RG-RAP2260(G). In the downloads section, you can find the firmware:

Once the firmware is downloaded, access your access point to the System -> Upgrade section.

Next, go to Local Upgrade and upload the file that was previously downloaded.

After it's uploaded, it will ask for confirmation. Click Ok, and the update will begin.

This way, the equipment is updated to version 1.86.1827.