switching a cosleeping toddler to their own bed

made the terrible mistake of cosleeping and now my almost 2.5 year old still sleeps in the bed. his dad is the main reason for that, he’s our first born and his dad is a total softy and he’d look at him in the bassinet and go “he looks so lonely”. i’m 23 weeks with baby number 2 and i made it VERY clear this baby WILL be sleeping in the bassinet next to the bed every night. but nowwwww i have to figure out how to get my toddler to sleep in his own bed. we have a one bedroom right now and recently applied for a 2 bedroom so our toddler can have his own room but there’s no point in that if he won’t sleep in it 🥲 so i think it’s best to get him used to sleeping in his own bed in a room w us and then when he gets his own room, he’ll be more comfortable sleeping in there. now the question is……how do i do that 😅 any tips are appreciated, thank you!!!