Always be your natural self
If you are being fake, or trying too hard, people will easily see through your new attitude, and you might end up becoming a joke. Therefore, it is always recommended that you never pretend to be someone you clearly are not. Always be your original self, do and say whatever comes naturally to you, and be happy about your own special identity. However, this does not mean that you do not need to improve your personality, or eradicate the flaws in your character. Whenever you decide to add to or subtract from your attitude, you will need to inculcate this change into your personality slowly.
Think before you adopt a new attitude
If you are fed up of being annoyed by others and want to change your attitude, you must thoroughly reflect on your personality first, and determine what exactly it is that is making you want to make a change. If you think deeply, and find a valid reason which prompts you to make a change, it is most likely that others will naturally accept your new attitude, owing to its genuine nature.
If someone is bullying you at work or school, you must change your meek and submissive attitude, and confront that person in order to make sure that such an act is not repeated in the future. This sudden change of attitude will be seen as a justifiable reaction to the treatment you were suffering from, and everybody will accept it as positive. In order to drive the point home, you can also file an official complaint, which will help everyone see you in a new light.
Always be humble
If you keep both feet on the ground all the times, you should not have to work too hard to make people accept your new attitude - as long as you are humble and likable, people are not likely to have a problem accepting your new attitude. Never be arrogant or rude to anyone; you should be friendly, optimistic, and always make an effort to have a smile on your face.
Dealing with someone whose behaviour is inconsistent and constantly changing can be exceedingly annoying. Whatever your attitude, make sure you stick to it, and do not decide to adopt a new attitude everyday - this will make it impossible for anyone to accept you or take you seriously. Adopting a new attitude for a couple of days, and then reverting to your old one is not going to work.