It is hard for some people to get rid of it once it's acquired.

Of course, the fear of death is partly innate, a side effect of the human condition. We're the only species that understands the story arc of our life ends in death. This has been described as a realization that is more than some of us can bear. So it's not nothing.

However, usually when someone seeks to "get rid" of this fear it's usually because the fear has been elaborated with religious ideation, and it's usually a person who is for whatever reason particularly vulnerable to the shame and blame game of many religions. These are people for whom the awareness of their mortality has been raised to a fever pitch of abject terror.

So the first question I'd ask a person is whether they are afraid of a particular dystopian afterlife concept such as the Christian hell, and what the predominant emotions associated with that are. And I'd want to know whether this was installed in their brain as a child, and if this dominates their thoughts much of the time. If that's the case I'd literally recommend therapy for religiously induced trauma.

If it's just the more universal dread of mortality then to me it is an issue of re-framing the concern in more realistic terms. Mortality is not something to be avoided, but rather to be understood as a part of life. If you live within your true scope and don't try to be something you're not (immortal, entitled to enjoyment and protection from suffering, etc) then you don't waste energy fighting reality, you simply accept it and live within its constraints on its terms. Much of the fear and loathing around mortality is fed by foolish attempts to negate or deny it. It's far better in the long run to embrace it and accept it and integrate it, the same as anything else that isn't maybe what you wish were true.

Now it may come to pass that science will eventually offer humanity biological immortality (the absence of disease or aging, where death can only occur by misadventure). Especially if that is broadly available AND affordable for all, then we will have to take a careful look at the pros and cons of that and possibly reframe the question again. But for now ... when it comes to death and taxes, the key is acceptance.