Here's what I do: Let the pears fully ripen, wash them and cut them in half and remove the core and stems. Freeze them until I am ready to use them. Recently I have started adding some pectic enzyme before freezing. It can start to work while they are thawing out. Then thaw them and mash them with a potato masher (in batches if necessary). Put them in a nylon mesh bag and add to the primary bucket. My largest batch so far was 3 gallons (4 gallons in primary), so I might have to make some adjustments if I was making a much larger batch.
I have a small (about 1 gallon size) fruit press, so I am considering pressing them after fermentation to remove more of the juice. Maybe I'll try that next time. But there is no need to press them beforehand, because freezing + mashing turns them into mush. This is for Bartlett pears. If you have a harder variety your results might be different.
I don't know if there would be any harm in leaving the seeds and stems in the primary.
I have a small (about 1 gallon size) fruit press, so I am considering pressing them after fermentation to remove more of the juice. Maybe I'll try that next time. But there is no need to press them beforehand, because freezing + mashing turns them into mush. This is for Bartlett pears. If you have a harder variety your results might be different.
I don't know if there would be any harm in leaving the seeds and stems in the primary.