It is not always so easy to get rid of negative ideas. There are times when we must go searching for the idea behind the idea. Some of those negative mantras serve us in ways that ways we do not admit to consciously.
When a person says something like, "...But I have been like this for 30 years!" What they are saying is, they are keeping "it." So how might something like hatred serve a person? Well, they don't have to take the risks of getting emotionally involved with someone else. Perhaps this allows them to stay by themselves more. The thing is, a person can stay by themselves in a more positive manner. They can be by themselves because they happily choose this.
There is quite a list of how to overcome negative mantras, which are thoughts like, "Geez, I am such a jerk!" "I am half-blind!" "Even my mother hates me!" "I am hopeless at math." "My cats are conspiring against me."
We brought up a few ideas already.
1. Cutting the binding cord in a ritual. (You gave one such spell in the previous post.)
2. Burning the negative ideas found while using affirmation technique. Someone sent me an interesting spell recently where you write the positive on the front of the paper and the negative on the back. You read the positive, giving them full energy. You release yourself from the negative in gesture and words. You burn the whole paper without ever reading the back of the sheet.
3. Hypnosis... There are gentle self-hypnosis and related techniques as well. Some of these I recently learned from Andrew Neblett and include simple acupressure points.
4. Meditation release through the root chakra. Interestingly enough, when the chakra above opens fully, which takes time and practice, the chakra below it resolves. This is assuming you are working from the root chakra up. The chakra above the root chakra is the reproductive or sex chakra. This is... the obvious. It does include ideas of reproducing yourself that you may not have thought of. Generating a family in the past, was a way to be productive on the farm as well. Also it is repeating your performances such as work production, ideas with others, etc. A sales person should have a beaming orange chakra. ;) They are sharing ideas with others in an attempt to share them together.
5. Karma includes thoughts. In creating with thought, the majority are subject to time and space. All those thoughts start to create. So you are now producing positive thoughts and find them stopped in their tracks. An individual may find they still have that sea of negativity. There are many ways to deal with this past thought karma. Recapitulation, regression, karma ritual, good deeds (Tonic for Tots!), and any process that goes back to deal with these old ideas. Karma ritual can also take the form of the more commonly known rituals such as ancestor worship, dealing with planetary afflictions in Vedic astrology.
6. Mantra... I prefer the old ones that tap into a sea of the millions of people (billions?) who have used them prior to me. They have been tested over time and some of them are from divine beings. Any process put in place by a divine being is always available for works is the rule. Some of the processes are very difficult, but mantra is easy enough.
I am sure others out there can add to the list.
The thing is, if the negative thought serves you somehow, and you do not go to the thought behind the thought, you will continue to bring it back. Look behind results of this thought and why you might hold onto it.