Dotted leaders in TOC

The default leader dots are too big and ugly. I can manually change them but doing it for the whole book would take too long. Is there a way to modify them, as one can modify the TOC text? I tried assigning a style to the one I modified but the style does not affect the dotted leaders. (The other lead-in choices are not good either.)

Depending on what is in your document, it may be easier to manually change.  However, here is a work around, if you so choose.  Tab leaders will be the font size you have selected when you put the leader in, so if you want your font to be 12 pt, but the leader to be 5 pt, you change your font size to 5 pt, then insert all your leaders, then go to Find and Replace, Special, Any Letter - then Replace With - select Font and change your font to whatever size you desire, but this does not change numbers, so you would have to repeat those steps to change any numbers as well.  HTH!!!

1. Unlink the TOC field. This is not easy to do in Word 2010. I copied the contents of the field to a different place in the document and pasted without the Content Control, then unlinked the pasted text. You also have to change the formatting of the entries to remove the hyperlink coloring and underline after you unlink the field.
   
2. Select the TOC
3. Replace ^t with ^t formatted to the smaller font size.

This will not change the size of the numbers. It should only be done when you are finished, though because it will have to be re-done if the TOC is modified. I suppose you could change the typeface, itself, to have a finer dot as well.