How to update my phone with insufficient phone memory?

How to update my phone with insufficient phone memory?
Added (1). My Nokia Lumia 530 can't perform a phone update because of insufficient space.
With only 400 MB free space, because of a 2.83 GB system excluding all other things, it can't perform the update requiring 850 MB of space.
And because of that, I can't install other applications that requires this software update.

Please, I need help.

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