Untested, but try something like this;
Code:
DEFINE OSC 4
DEFINE OSCCAL_1K 1 ' load factory osccal value

'Register Initializations'
ANSEL = 0          ' all digital
CMCON = %00000111  ' set all pins to digital
TRISIO = %00011111 ' define Inputs and Outputs
GPIO = %00000000   ' set all pin states to off
WPU = %00000000    ' shut off weak pull ups
OPTION_REG = %01010001 ' set the tmr 0 to prescale of 1:4 for 1ms roll over
INTCON = %10100000 ' ENABLE THE TMR0 INTERRUPTS

'Variables'
LED VAR GPIO.5
ROLLOVER_COUNTER VAR WORD
SECONDS VAR BYTE

LED = 0 ' LED off on boot

ON INTERRUPT GOTO ROLL_OVER

MAIN:
  IF SECONDS = 5 THEN
     ROLLOVER_COUNTER = 0
     SECONDS = 0
     TOGGLE LED
  ENDIF
  GOTO MAIN

DISABLE
ROLL_OVER:
  ROLLOVER_COUNTER = ROLLOVER_COUNTER + 1 ' INCREMENT ROLL COUNT 1 EVERY 1 ms
  IF ROLLOVER_COUNTER >= 1000 THEN 'created to count seconds instead of ms
     SECONDS = SECONDS + 1
     ROLLOVER_COUNTER = 0
  ENDIF
  INTCON.2 = 0 
  RESUME
  ENABLE 
  
  END