When cooking 2 Honey Baked Ham frozen sides, how do I need to change temp or time?
The second item needs to be in the oven for 15 minutes more than the first item.  Just put that item in the oven, then put the second item in 15 minutes later.  Follow all other procedures as indicated in the instructions. The required cooking temperature is the same for both. I am assuming that cooking from frozen is built into the instructions, so that will not really matter for your question. The temperature will drop a bit when you open the oven door, but your oven will catch up in a reasonable amount of time and will not impact the final cooking.  Just make sure there is a bit of space between your products when they are both in the oven.