How to change external bottom bracket cups?
Change external bottom bracket cups is not difficult and requires only one specific tool: a bottom bracket spanner.
Typical tools: 5mm Hex Wrench / Bottom Bracket spanner / Mallet / Grease
Install correct spacers as needed (68mm bottom bracket shell: 1 spacer on left side, 1spacer on right side. 73mm bottom bracket shell: 1 spacer only on right side). Thread new cups clockwise into left side and counterclockwise into right side.