Let kids learn in a more natural way. Instead of confining your kids to desks, let them sit outside and read a book. Don't try to turn everything into a lesson; let them ask you questions. Take them out on nature walks or to museums, and let them be the ones asking you questions so that they explore their natural curiosity.
Create a structured schedule so the kids know what they're supposed to be doing and don't drift into unproductive activities. Be involved and there to help them with activities, such as science projects or math questions. Give them some independence to explore the subjects, but make sure they have direction as well.
Set up activities with other homeschooled kids. Kids who have been in schools are used to being around their peers, and suddenly having to be without them can be a big obstacle to the transition to homeschooling. Develop close relationships with other homeschoolers and set up regular educational activities with them.
Get connected with other homeschooling parents. It's not only important for your kids to transition to homeschool, but also for you to receive advice and encouragement along the way. Set up times where not only your kids can meet up with other kids, but where you can meet the kids' parents and establish that relationship.
Give it time. Sometimes kids just need to adjust naturally to a new and different learning environment. Don't expect kids to simply jump right into activities when they're used to a different way of learning. It may take time for you to get used to the homeschool life as well.