Inkscape

Inkscape is professional quality vector graphics software, uses the open standard SVG (Scalable Vector Graphics) as its native format.

Change lines thickness of eps converted PDF

Start by

inkscape

Or Right click pdf file, Open With -> Other Application -> Use a custom command -> inkscape
Select OK for the PDF import settings

Resize canvas to image

Shift+Ctrl+d (File->Document properties).

Inkscape version 0.47: Alt+f (Fit page to selection)
Inkscape version 0.48: Alt+z, Alt+r (Resize page to content -> Resize page to drawing or selection)

Line size change - fill and stroke

With the Black arrow tool, Click on a Top in the spectrum, which will expand a selection box for the whole 1H,N15 area.
Shift+Ctrl+F (Object->Fill and stroke), Stroke style, set Width 1.000 px, enter

Modify a text or a label object

With the Black arrow tool, double Click on a Label in the spectrum, which will expand a selection box.
You can switch between "rotation mode" or "Stretch mode" by clicking once one the object, with With the Black arrow tool.

Saving

As pdf

File -> Save as: test2.pdf

As png

This way sets the background "Transparent"

File -> Export bitmap -> Page
Set 200 dpi

Rotate object - Transform

Shift+Ctrl+m (Object->Transform)