This afternoon I replaced the chain on my Bob Jackson World Tour, I expect I have had approaching 2,500 miles from it in all weathers including heavy winter. I noticed last week it had just hit .75% stretch and didn't want to risk damage to the cassette or chainrings.
Although the running gear on my Bob Jackson is a mix of Shimano 105 and Ultegra, with a Sugino Alpina chainset, I installed another Dura Ace chain as I am convinced they are quieter running than 105 or Ultegra. This time I took the opportunity to install a Wippermann Connex link that allows the chain to be easily removed and replaced for cleaning. I always used them on my Surly Cross Check as it was easy to clean after off-road riding but for some reason haven't bothered on the World Tour until now. For chain breaking, I use a Park Tool Ct-5 chain tool, good value for money, excellent quality and easy to use.
Installation is straightforward, after breaking the new chain to match the length of the old one, just remove the outer plates from the other end, wrap and pop in the links. There is a correct way round, the outer plate should have the opening end leading and the flatter profile facing inward on the chainring, the picture above shows the view of the chain on the top side of its travel, between the cassette and chainring. Finally, a quick lube of the chain, I always use Chain-L as I find it very durable and gives me very quiet running. I also took the opportunity to remove and re-grease the jockey wheels from the rear derailleur, I try to do this annually at least. The whole job was probably about 20 minutes, just in time for the rain!