Need instuctions for the marathon mod.sto83000ye user manual

https://www.timex.com/watch-manuals.html
Search for Marathon - its there.

how do i decrease the year?

Download the pages and then delete the unnecessary pages you won't ever use.

I'm guessing that your watch is described here
http://www.walmart.com/ip/Marathon-by-Timex-Digital-Mid-Size-Black-and-Silver-Tone-Watch/38229915
(at the bottom it says model = T5K805, name is marathon)
[also on Amazon - http://www.amazon.com/Timex-Womens-Marathon-Sports-Digital/dp/B00R4XTAJ8/ref=sr_1_3?s=apparel&ie=UTF8&qid=1421449802&sr=1-3&keywords=t5k805&pebp=1421449828860&peasin=B00R4XTAJ8)

Then.look down the list for marathon in this http://www.timex.co.uk/info/product-manuals-downloads
and choose the one of the three you want. The non GPS one is very short and not really what I'd call a manual. I hope this is what you need. Otherwise contact Timex

16.January.2015

http://www.timex.com/info/Product_Instruction_Guides_Downloads

There are two ways to find the user manual for your Timex watch.

1. Find your watch on the list below and click on the language link for your manual.

2. Find the 3-digit module number located on the caseback of most Timex products and click on the corresponding language link for that number in the Module Table at the bottom of the page.

http://assets.timex.com/user_guides/W15_M774/W15_M774_NA_EN.pdf ??

You can get instructions from the Timex web site "timex.com".

At the bottom of the screen click on "manuals/downloads", then on "product
manual download"

Enter your watch type in the search box and click on "search"

Hi,

I lost a user manual, then found these guys. They emailed it to me in about 2 hours and it only cost about £3, which i thought was very reasonable.

http://findmymanual.com/

Hope this helps.
Jane