I have been playing for about 2 months and my changing of chords getting alot faster and smoother. It is not perfect but I am still working on it. I asked the same question about a month ago and everybody said practice and I sat down that day and practiced changing chords (not strumming just changing chords) for about 2 hours and I
noticed the next day I was alot better. It just takes practice, happy strumming.