To easily change flight details with AllegiantAirlines, you have a few options:

Online through Allegiant's Website or Mobile App:

Visit Allegiant's official website or use their mobile app.
Navigate to the "My Trips" or "Manage My Booking" section.
Enter your booking details (confirmation number and last name).
Follow the prompts to modify your flight details, such as date, time, or seats.
Calling AllegiantAirlines Customer Service:

Contact AllegiantAirlines customer service directly.
Use the phone number provided on their website or app.
Provide your booking details to the customer service representative.
Request the changes you want to make to your flight details.
Visit a AllegiantAirlines Ticket Office or Airport Counter:

If you prefer face-to-face assistance, visit a AllegiantAirlines ticket office or airport counter.
Have your booking information ready to provide to the staff.
They will assist you in making the necessary changes to your flight details.
Through your Travel Agent (if booked through one):

If you booked your Allegiantflight through a travel agent, contact them directly.
They can assist you in changing your flight details according to Allegiant's policies.
When changing flight details, be prepared for potential fees or fare differences, depending on the fare rules and the changes you are making. It's a good idea to check Allegiant's policies regarding changes and cancellations before proceeding.