Hodir will shatter his rare cache after 3 minutes, so you'll need to have heavy DPS. In most cases, the raid will be wearing Frost Resist gear, so keep this in mind. Having as many ranged members as possible is helpful because they can stay near the cozy fires and keep up the singed buff. It also helps to always free the mage first. Most times you can ignore the other NPCs as she will get them out of their ice blocks and give you a few more seconds of DPS on Hodir. Also be sure to use the crit buff from the Storm Cloud to your full advantage. This is another reason why it helps to have a lot of ranged DPS.