The respected jethros.org.uk site has published the following withdrawal schedule for the Boeing 747-400 and Boeing 767-300ER fleets:

Boeing 747-436 G-BNLM November 2013
Boeing 747-436 G-BNLR January 2014
Boeing 747-436 G-BNLE February 2014 (New First)
Boeing 767-336ER G-BNWN March 2014
Boeing 747-436 G-BNLT April 2014 (New First)
Boeing 767-336ER G-BNWU April 2014
Boeing 767-336ER G-BNWC May 2014
Boeing 747-436 G-BNLS May 2014
Boeing 767-336ER G-BNWH June 2014
Boeing 767-336ER G-BNWO June 2014
Boeing 767-336ER G-BNWD July 2014
Boeing 747-436 G-BNLI August 2014
Boeing 747-436 G-BNLF September 2014
Boeing 747-436 G-BNLW October 2014
Boeing 747-436 G-BNLG July 2015 (New First)
Boeing 747-436 G-BNLU October 2015 (New First)
Boeing 747-436 G-BNLV November 2015 (New First)
Boeing 747-436 G-BNLX November 2015
Boeing 746-437 G-BNLZ January 2016.

Some or all Old First fitted Boeing 747-436s G-BNLJ, G-BNLL, G-BNLY, G-CIVA, G-CIVB and G-CIVC will be fitted with New First seats removed from withdrawn aircraft.