It is important to know that an efficient office removal cannot be organised in one week. The longer you plan, the better the final result. You need time to evaluate your employees' needs, your business needs and to arrange all the necessary help.
It's not just about the removal itself. You probably do not want to create any problem to your work environment: you should make the transition from one office to another as smooth as possible. Try to make use of the weekend, so that your business can continue to operate without interruptions.
Let your staff know about the removal schedule. Ask them to pack their desk items and label them correctly. Communicate as much as you can so that they will understand every single aspect of the move and organise their work accordingly. Show them the new floor plan so that they will be able to visualize the new office beforehand. You can also think about creating new staff groups to make a better use of the new space. Do not allow them to do moving work like lifting heavy items. Also, celebrate with them and clearly explain how the new office will make everyone's life much easier!
The right company
Go DIY is probably a bad choice. A good office removal company can execute the office move in a very limited amount of time. Make sure you have a clear idea about the cost of the service with a full quote including office inventory, insurance and packing/unpacking of all office equipment and furniture. Ask other business owners for a recommendation. Do not trust companies who tell prices on the phone: they can provide an exact quote only looking at the office you are in and getting detailed information about the new one you are moving to. Make sure they have been in business for a while, their quote has no hidden extra fees and they own removal equipment.