In any body field that has a WYSIWYG editor toolbar, use Omega icon

From the special character options, select the special character you want.

Windows keyboard instructions

Use the Omega icon in the WYSIWYG body field, then cut and paste into any field.

OS X keyboard instructions

In some Drupal fields, the WYSIWYG editor is not available (example: the title field). On certain platforms, you can use keyboard shortcuts to insert the special characters as an alternative.

Steps: Click 'option' on your keyboard + 'the accent character" as listed below

Accent: Grave  `

Key Strokes: option + `; then the character

Available Characters: À È Ì Ò Ù à è ì ò ù

Accent: Acute  ´

Key Strokes: option + e; then the character

Available Characters: Á É Í Ó Ú á é í ó ú

Accent: Circumflex ^

Key Strokes: option +  i; then the character

Available Characters: Â Ê Î Ô Û â ê î ô û

Accent: Tilde  ~

Key Strokes: option + n; then the character

Available Characters: Ã Ñ Õ ã ñ õ

Accent: Umlaut ¨

Key Strokes: option + u; then the character

Available Characters: Ä Ë Ï Ö Ü Ÿ ä ë ï ö ü ÿ

For other special characters, refer to this list: https://forlang.wsu.edu/help-pages/help-pages-keyboards-os-x/