First of all, make sure that the change is going to affect your business and you have to make plan to deal with that change.
Immediately start communicating to staff members about the change and let them know that they have to get accommodated with the transition period in order to cope up with the cut throat competition.
Instead of sending emails to staff members, try to engage them with direct communication which will bring positive results and the transition period will not affect the production.
Personal communication always brings good results and considering this, you should talk to all employees one on one basis in order to get their attention.
Try to set goals for the staff members during the transition period and encourage them to achieve those targets. It will not only motivate them but will also help them in getting accommodated with the changing conditions easily.
Stay well aware about the mindset of your staff members and try your best to resolve their problems during the transition period. Do not let them down if they find it difficult to cope up with the changing condition.
Keep encouraging your staff members by appreciating their efforts in getting familiar with the change in business. Always be first to talk to employees to ensure them that they have the ability to handle the circumstances.