Upgrade Your Macbook Pro (SSD Upgrade, RAM Upgrade, Optical Drive Bay Adapter) - YouTube
15-inch MacBook Pro Mid 2009 Memory Installation Video - YouTube
RAM Upgrades For Apple MacBook (2009 - 2010) from OWC
Restored Apple Macbook Pro 13.3-inch (Retina) 2.7Ghz Dual Core i5 (Early 2015) MF839LL/A 128GB SSD 8 GB Memory 2560x1600 Display Mac OS X v10.12 Sierra Power Adapter Included (Refurbished) - Walmart.com
MacBook Pro 17" Mid 2009 EMC 2329 - used original spareparts for Macs
A-Tech 16GB Kit (2x8GB) DDR3 1066MHz / 1067MHz PC3-8500 SODIMM RAM for Apple MacBook (13 inch, Mid 2010), MacBook Pro (13 inch, Mid 2010), iMac (27 inch, Late 2009), Mac Mini (Mid 2010) at Amazon.com
It's old as heck but still kicking! Mid 2009 MacBook Pro (MacBook Pro 5,5) I'm hoping to use opencore legacy patcher to install Monterey on it. : r/ macbookpro
Replace your 2009-2012 MacBook Pro HD with an SSD
MacBook Pro: How to remove or install memory - Apple Support
A-Tech 16GB Kit (2x8GB) RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
MacBook Pro 15" Unibody 2.53 GHz Mid 2009 - iFixit
How to Upgrade MacBook Pro RAM (2009, 2010, 2011, 2012): EveryMac.com