How to just do comment or uncomment?

[peter-lyr]

  extra = {
    -- Add comment on the line above
    above = 'gcO',
    -- Add comment on the line below
    below = 'gco',
    -- Add comment at the end of line
    eol = 'gcA',
  },

For example. Just like the code above. The cursor is inside { and }. I want to just uncomment inside { and }, resulting like this:

  extra = {
    Add comment on the line above
    above = 'gcO',
    Add comment on the line below
    below = 'gco',
    Add comment at the end of line
    eol = 'gcA',
  },

But I have to uncomment one by one manually.

It's Ok if I want to comment inside { and } by typing gci}. But it's not always what I want.

Is there a mapping like gui} for example to uncomment inside { and }?

btw, I think it's good to invert the commeted and uncommeted.
for example, when typing gcii} will make the code most above to be like this:

  extra = {
    Add comment on the line above
    -- above = 'gcO',
    Add comment on the line below
    -- below = 'gco',
    Add comment at the end of line
    -- eol = 'gcA',
  },

Thx.